Means for lubricating work in sheet forming machine operating on forming-by-drawing principle



Dec. 8, 1959 F- ANDERSON 2,916,075

MEANS FOR LUBRICATING WORK IN SHEET FORMING MACHINE OPERATING ON FORMING-BY-DRAWING PRINCIPLE v Original Filed Feb. 8. 1955 5 Sheets-Sheet l INVENTOR FQOHMAN ANDERJ N ATl'bRNEY Dec. 8, 1959 MEANS FOR LUBRICATINC F ANDERSON WORK IN SHEET FORMING MACHINE OPERATING ON FORMING-BY-DRAWING PRINCIPLE Original Filed Feb. 8, 1955 5 Sheets-Sheet 2 A TTOP/VFY ING WORK IN SHEET FORMING MAC FORMING-BY-DRAWING PRINCIPLE F. ANDERSON ING WORK IN 2,916,075 SHEET FORMING MACHI BY-DRAWING PRINCIPLE 5 Sheets-Sheet 4 MEANS FOR LUBRICAT OPERATING ON FORMING- Original Filed Feb. 8. 1955 Dec.'8, 1959 F. ANDERSON 2,916,075

MEANS FOR LUBRICATING WORK IN SHEET FORMING MACHINE OPERATING ON FORMING-BY-DRAWING PRINCIPLE United States Patent MEANS FOR LUBRICATING WORK IN SHEET FORMING MACHINE OPERATING ON FORM- ING-BY-DRAWING PRINCIPLE Frohman Anderson, Las Vegas, Nev.

Original application February 8, 1955, Serial No. 486,773, now Patent No. 2,851,080, dated September 9, 1958. Divided and this application November 22, 1957, Serial No. 698,236

7 Claims. (CI. 153-32) This application is a division of application Serial No. 486,773, filed February 8, 1955, now Patent No. 2,851,- 080, which relates to a machine for shaping metal sheets into compound curves by pulling the sheets edgewise from one end to the other over a series of forming elements the working faces of which differ in contour transversely of the sheets and are disposed in stepped relation, a restraining or hold-back force being exerted on the sheets in opposition to the pulling force to subject the sheets to a stress beyond their yield point. This operation in the parent case is termed forming-by-drawing.

In the forming passage of the sheet through the machine there are three stages of operation. The hold-back force is applied at the first stage which determines the general path of movement of the sheet, and the second and third stages have each a draw-over forming element disposed so as to cause the sheet to be engaged on its reverse sides as it passes over them.

Atthe first stage which constitutes the hold-back stage, opposing elements define a slot through which the sheet is drawn and the width of which is regulatable to determine the restraint applied at this stage. Both surfaces of the sheet are therefore subjected to substantial friction as the sheet passes through the first stage and is drawn over the forming elements of the second and third stages.

To minimize surface abrasion of the sheet during its forming operation it is necessary to protect both surfaces and this invention contemplates a way to apply a coating of lubricating oil to the surfaces of the sheets in advance of their being engaged by hold-back and cooperative forming elements at successive stages.

For this purpose means are provided in accordance with the invention to apply lubricating oil to both sides of the sheets just before they enter into the zone of restraint or hold-back, and also to apply oil to both sides at a plurality of points during their passage through the restraining zone. 7

The invention will be described by reference to the embodiment illustrated in the accompanying drawings in which Fig. 1 is a transverse section through the machine on line 1-1 of Fig. 3, showing the first or hold-back stage structure in elevation and the base structure and main uprights and a fragmentary portion of the draw-bench structure in section;

Fig. 2 is a fragmentary sectional detail taken on line 22 of Fig. 1;

Fig. 3 is a longitudinal section of the forming structure of the machine taken on line 33 of Fig. 1;

Fig. 4- is a longitudinal section on an enlarged scale of a portion of the forming structure and of the draw head taken on line 4--4 of Fig. 1;

Fig. 5 is a fragmentary section of the forming structure taken on the line 5-5 of Fig. 4;

Fig. 6 is an enlarged sectional detail of a lubricating control valve, taken on line 6-6 of Fig. 5;

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Fig. 7 is an enlarged central vertical section of the forming elements and immediately associated portion of the forming structure, showing a modified form of the second and third stage-forming elements;

Fig. 8 is a fragmentary isometric view of the lubricating bar;

Fig. 9 is a diagrammatic plan of the lubricating system for the sheets; and

Fig. 10 is a diagrammatic elevation of the same.

The three main components of the machine as a whole are the forming structure consisting of the three stages through which the sheets are pulled, the draw bench mechanism including a stationary elongated channel guide and a sliding carriage which is propelled by a powerdriven bull gear, and the pulling mechanism including a draw head that is attached to and moved by the carriage. The draw bench and the draw head are only incidentally and incompletely illustrated and they will "be referred to only in connection with their function in pulling the sheet through the forming structure.

The forming structure has a sub base 10 on which is a main base 11. Suspended on the main base by a gimbal support 12 for freedom of movement about two axes at right angles to each other, one longitudinal and one transverse of the machine, is a guide structure 13 in which is guided the first and third stage body members in a certain dynamic movement not related to the present invention.

The forming elements of the three stages are contained between two uprights 14 and 15 which are supported upon and attached to the base structure, as shown in Fig. 1.

The first stage structure includes an upper and a lower hold-back assembly which are contained between two secondary uprights 16 and 17. The lower assembly comprises a T-shape body member having a hollow cross head 18 anda hollow rearwardly extending leg 19 which is supported in the guide structure 13. On top of the cross head 18 is a removable hold-back element 20 which has a dove-tail fit at the front edge and is clamped in place by a clamp plate 21 which is secured in place by screws 22. Behind the element 20 a smoothing plate 23 has a dove-tail fit on top of the cross head and is clamped in place by a clamp strip 24. The cross head 18 has a downward extension 25 which rests upon and is guided and supported by the guide structure 13 and, as shown in Fig. 3, has an opening for the admission and passage through it of the rearwardly extending leg of the T-shape third stage body member. 0

The cross head 13 is fixedly attached at its ends to the secondary uprights 16 and 17 and these uprights have a freely slidable bearing support within the main uprights 14 and 15 through rocker bearing plates 26 which have a universal joint connection with their respective secondary uprights to permit of a freedom of movement of the first stage structure which is not related to the present invention.

The upper hold-back assembly comprises a ram slidable in the secondary uprights and having a hold-back element opposing the element 20.

The upper assembly has a top fixed plate 27 which spans the secondary uprights 1-6 and 17 and is adjustable in height between gibs 28 on the uprights to compensate for variation in thickness of sheets being formed. For this purpose the gibs and the ends of the bar 27 are notched, as shown in Figs. 1 and 2, and blocks 29 are inserted on the bottom of the notches in the bar, shims being inserted on top of the blocks the thickness of which determines the upward limit of movement of bar 27. Screws 30 pass through bridge pieces on top of the gibs and screw into the top edge of bar 27 a distance which determines the limit of movement of bar 27. A

tie bar 31 behind bar 27 connects and braces the top ends of secondary uprights 16 and 17.

A ram 32 is a cross bar spanning the secondary uprights and guided in gibs 33. The fixed bar 27 and the ram 32 are connected by toggle 34 and toggle 35 connected by bar 36. The upper link 37 of toggle 35 has an upward extension forming a lever arm to which the power is applied. A hydraulic cylinder 38 has trunnions in bearing brackets 39 on top of the fixed bar 27, with its piston rod connected to the top end of toggle arm 37. The lever arm 37 is double, the rear arm being slightly wider than the front arm, as indicated by dotted lines in Fig. 1, and the bar 27 is hollow.

The lower links of the toggles are pivotally connected to the back face of ram 32, and the bottom edge of the ram has a dove-tail groove into which fits the complementary shaped face of a removable hold-back element 40 which is clamped in place by clamp strip 41.

Back of the ram 32 and element 40 is a full length plate 42 which opposes plate 23 and cooperates therewith to smooth and flatten out the entering sheet. This plate 42 is secured on the bottom of a plate carrier 43 that runs the full length of the ram and has a lost motion connection therewith. The plate carrier is a member rectangular in cross-section somewhat higher than it is wide and is hollow in its upper portion to provide a chamber to receive lubricating oil, as will later appear, and has arch-shape openings in its bottom to accommodate the screws 44 which secure the clamp plate 41. The bottom of the plate carrier is broader than the superstructure and the plate 42 has a dove-tail fit with the bottom, being secured thereto by clamp 45.

The plate carrier 43 has a lost motion connection with the ram '32 and engages the rear gib 33 which holds the ram and plate carrier with their adjacent faces abutting. The lost motion connection between the ram 32 and plate carrier 43 is illustrated in Fig. 1. Headed screws 46 are screwed into the top of the plate carrier 43 near each end and pass through holes in angle brackets 47 on the rear face of the ram. The screws are adjusted in length so that their heads are above the bracket flange a predetermined distance when the ram and plate 42 are both down. Therefore the ram moves up the predetermined distance before picking up the plate.

The ram 32 carries the plate carrier 43 down with the ram through an angle bracket on the back of the ram which supports the plate carrier through the medium of a yieldable cushion connection shown in Fig. 3 as a cup 43a on the plate carrier which contains elastic rings (not shown), such as rubber.

Beyond the first or hold-back stage are the second and third stages which are designated generally by the legends 2nd and 3rd, respectively. The sheet S is pulled through the three stages by a draw head having jaws which grip the leading edge of the sheet, as partially shown in Fig. 4. This draw head is propelled by a carriage 48 which is actuated by a bull gear 49 engaging a rack on its under side and is guided in a channel-shape draw bench 50, as partially shown in Fig. l and diagrammatically shown in Fig. 9.

As above stated, oil is supplied to both surfaces of the sheet before it enters between the smoothing plates 23 and 42, and also just before it is engaged by the first stage hold-back elements and While it is passing between those elements. The means for lubricating the sheet will now be described.

The course of the oil is through the hollow interior of the T-shape lower member and from thence through distributed oil passages to the lower side of the sheet and also through upward passages in the secondary uprights 16 and 17 into the hollow interior of plate carrier 43 and thence through distributed passages to the top of the sheet. The used oil drips back into the oil sump of the main base 11 from where it is forced through filters into a storage tank. A motor'driven pump delivers oil under pressure to the lower T-shape member.

The hollow interior of the rearwardly extending leg 19 is designated 19a and this communicates with the hollow interior of the lateral arms of the head 18 through holes 18a. Holes 18b in the ends of the head 18 register with lateral passages in the secondary uprights 16 and '17 leading to vertical passages 51 which at their upper ends lead into side openings 52 in the ends of the hollow interior of the plate carrier 43.

Along the arms of the cross head 18 spaced not more than two inches are a number of individual groups of oil-conducting passages in the top of the head communicating with the hollow interior, each group comprising trunk and branch passages. For each group a hole consituting the trunk passage is bored through the rear wall and into the front wall of the head for an oil valve plug '53 and from this hole lead upward branch passages 54 and 55 (Fig. 6) and a continuation of the hole leads to upward branch passage '56 (Figs. 4 and 7).

The passages 55 leads to a lubricating bar 57 (Figs. 7 and 8) which has upward passages to the under side of the sheet in depressed portions of the top face of the bar and is disposed between the plate 23 and lower holdback element 20. Element 20 has through passages 58 and 59 leading to the bottom of convolutions in its top surface and communicating with a manifold recess 60 in the bottom of the element with which passages 56 communicate. Each passage '54 communicates with a passage in clamp 24 leading to the underside of the sheet.

The plug 53 is designed so that when'it 'is pushed in to the position of Fig. 6 it shuts off the oil from the passages 54, 55 and 56, and when it is pulled out as shown in Fig. 4, it opens the oil passages to the interior of the head 18. Thus the passages which are outside the width of the sheet may be shut oflf. A pin 61 engages in a slotted end of the plug and limits the inward movement of the plug and also prevents it from turning. This is necessary since a out-out 530 in the top of the plug provides communication to the passage 54 when the plug is pulled out.

From the interior of plate carrier 43 the oil passes un der pressure through similarly spaced groups of oil-conducting passages, each group comprising trunk and branch passages which lead to the top sheet, and plugs 53a control the inlet to these passages. These plugs in their innermost position, as shown in Figs. 4 and 7,-close off the admission of oil from the interior of plate carrier 43 to the respective passages and when retracted the plugs open communication of the passages with the interior of the plate carrier.

For each group of oil-conducting passages made up of the individual trunk and branch passages, the oil passes first to a vertical passage 62 in the wall of the plate carrier and thence into a lateral passage 63 in the ram 32, which together constitute the trunk passage, and thence branches into two downward branch passages 64 and 65 in the ram. The downward passage 65 leads to a manifold recess in the top of element 40, and for each passage 65 two-passages in the element 40 lead from this recess to the bottom of convolutions in the sheet engaging face of the element. The other downward passage 64 of each individual group communicates with a passage 66 between the plate 42 and the bottom of the plate carrier 43, which passage 66 discharges through a passage in clamp 45 on to the top of the entering sheet S.

The used oil drips down into the oil sump in the main base 11, as indicated by the arrows in Figs. 9 and 10. Some of the oil drips over the edges of the sheet as it passes through the first stage and more is scraped off as the sheet enters the second and third stages, running down in the space between the first and third stages. There is some drippage from the bottom as the sheet emerges from the third stage, which falls on to a third stage cross head 67 and collects in a longitudinal groove the 68 in the head and runs down through spaced passages 69 into the passage leading to the sump.

From the sump the oils runs out of opening 70 (Figs. 9 and into pipe 71 whence it runs into tank 72 disposed alongside the sub base 10 and providing a support for motors M5 and M6 and pumps P5 and P6 driven by the respective motors. At the right of tank 72 is a clean oil tank 73 having a filter 74 mounted thereon.

Pump P5 is the pressure or delivery pump and pump P6 is the suction or return pump. The pump P6 has suction pipe 75 extending into tank 72 and delivery pipe 76 leading to filter 74 from which pipe 77 leads into the clean oil tank 73. From the clean oil tank pump P5 draws oil through pipe 78 and delivers the oil through pipe 79 to the hollow interior 19a of the rearwardly extending leg 19. A valve 80 in pipe 79 provides a shutoff for the oil (Fig. 3).

The sheet-lubricating system shown in the drawings and above particularly described is, of course, susceptible of modification within the principle and scope of the invention as defined in the following claims:

What is claimed is:

1. In a forming-by-drawing machine, a first stage hold-back structure and means for lubricating a work piece being drawn therethrough comprising a pair of uprights, a T-shape lower hold-back member having its cross head spanning and secured to the uprights and its leg extending rearwardly, the cross head and leg being hollow, means to supply oil under pressure to the hollow interior, a plurality of spaced oil ducts leading from the hollow interior of the cross head to the top portion of the cross head in front and to the top portion in rear of the hollow interior, a removable hold-back element secured on said front top portion and having oil passages therethrough communicating with the duct leading to said portion, a work engaging lower guide plate disposed on top of the cross head back of the hold-back element, and a clamp for the rear edge of guide plate, said clamp having spaced oil passages therethrough communicating with the ducts leading to the rear top portion of the cross head.

2. The mechanism defined in claim 1 together with individual manually operable valve plugs for the ducts.

3. The mechanism defined in claim 2 in which the ducts to the said front top portion have branches leading to the space between the hold-back element and the guide plate, together with a lubricating bar in said space having oil passages communicating with said branch ducts and conducting oil to the under side of a work piece being drawn thereover.

4. In a forming-by-drawing machine, a first stage holdback structure and means for lubricating a work piece being drawn therethrough comprising a pair of uprights, a T-shape lower hold-back member having its cross head spanning and secured to the uprights and its leg eXtend ing rearwardly, the cross head and leg being hollow, means to supply oil under pressure to the hollow interior, a vertically movable ram spanning the uprights and guided thereon above and in opposition to said cross head of the lower hold-back member, an oil chamber carried by the ram, a passage in at least one of the uprights connected with both the hollow interior of the cross head and with said oil chamber, and ducts leading from the oil chamber to the lower face of the ram.

5. The mechanism defined in claim 4 together with individual manually operable plugs for the ducts.

6. The mechanism defined in claim 4 together with a removable hold-back element secured on the lower face of the ram and having oil passages therethrough communicating with the ducts leading to said lower face.

7. The mechanism defined in claim 6 together with a lower guide plate carried by the said cross head, an upper guide plate on the bottom of the oil chamber opposing the lower guide plate and having its top face contacting the lower face of said bottom, oil passages formed in one of said contacting faces and leading to the front and rear edges of the upper guide plate, and branch ducts from oil chamber leading to said oil passages.

References Cited in the file of this patent UNITED STATES PATENTS 2,480,826 Anderson Sept. 6, 1949 

